On Tue, 13 Apr 2010 08:59:38 -0700 (PDT), Frogwatch
wrote:

This problem with bungee material deteriorating in sunlight is so bad
that I have actually sewn covers for bungee from scrap material.
Somebody should make UV resistant bungee.

We have one piece of bungee cord on the trawler which lives up on the
bow pulpit and is totally exposed to direct tropical sun every day.
It typically lasts about a year before the cover deteriorates. Given
the harsh environment and low cost of replacement, that seems
reasonable to me.

Used on or near the under side of a trailer, in a more northerly
climate, for 6 months or so of the year, it seems reasonable to expect
multi-year life. I had exposed bungee cord on my old sailboat in
Connecticut which seemed to last at least 3 or 4 years if not kept
under constant high tension.